U.S. patent application number 12/988119 was filed with the patent office on 2011-02-17 for rheology influencing additive for mineral building materials.
This patent application is currently assigned to AKZO NOBEL N.V.. Invention is credited to Erwin Buhler, Hanspeter Waser.
Application Number | 20110039984 12/988119 |
Document ID | / |
Family ID | 39495219 |
Filed Date | 2011-02-17 |
United States Patent
Application |
20110039984 |
Kind Code |
A1 |
Buhler; Erwin ; et
al. |
February 17, 2011 |
RHEOLOGY INFLUENCING ADDITIVE FOR MINERAL BUILDING MATERIALS
Abstract
The present invention pertains to a rheological additive to
replace casein in minerally setting building material compounds,
characterized in that the rheological additive contains at least
two different dispersing agents and at least one stabilizer, or at
least one dispersing agent and at least two different stabilizers,
wherein said at least one dispersing agent is or said at least two
dispersing agents are selected from the group of lignin sulfonate,
polycarboxylate, polycarboxylate ether, melamine formaldehyde
sulfonate, alkylphenol glycol ether and/or naphthaline sulfonates,
and said at least one stabilizer is or said at least two
stabilizers are selected from the group of modified or unmodified,
fully or partially hydrolyzed polyvinyl alcohol, polyvinyl acetal,
polyvinyl pyrrolidone, polyalkylene glycol, polyalkylene oxide,
agar-agar, carob seed grain, pectin, poly(meth)acrylate and/or
(meth)acrylate thickeners, poly(meth)acrylamides, polyurethanes,
associative thickeners, gelatine and/or soy protein. In addition, a
process for the preparation of the additive, the use of the same,
as well as minerally setting building material compounds containing
the rheological additive are described.
Inventors: |
Buhler; Erwin; (Sempach,
CH) ; Waser; Hanspeter; (Hildisrieden, CH) |
Correspondence
Address: |
KENYON & KENYON LLP
ONE BROADWAY
NEW YORK
NY
10004
US
|
Assignee: |
AKZO NOBEL N.V.
ARNEHM
NL
|
Family ID: |
39495219 |
Appl. No.: |
12/988119 |
Filed: |
April 10, 2009 |
PCT Filed: |
April 10, 2009 |
PCT NO: |
PCT/EP09/54356 |
371 Date: |
October 15, 2010 |
Current U.S.
Class: |
524/5 ;
524/320 |
Current CPC
Class: |
C04B 2103/0079 20130101;
C04B 2111/1006 20130101; C04B 40/0039 20130101; C04B 2111/62
20130101; C04B 40/0039 20130101; C04B 24/18 20130101; C04B 24/2664
20130101; C04B 24/383 20130101; C04B 24/223 20130101; C04B 40/0039
20130101; C04B 40/0039 20130101; C04B 24/383 20130101; C04B 24/2623
20130101; C04B 24/32 20130101; C04B 24/2647 20130101; C04B 24/226
20130101 |
Class at
Publication: |
524/5 ;
524/320 |
International
Class: |
C04B 28/00 20060101
C04B028/00; C08K 5/092 20060101 C08K005/092 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 16, 2008 |
EP |
08154650.9 |
Claims
1. A rheological additive suitable for use in a minerally setting
building material compound, the rheological additive comprising: at
least two different dispersing agents and at least one stabilizer,
or at least one dispersing agent and at least two different
stabilizers, wherein said at least one dispersing agent is or said
at least two dispersing agents are selected from the group
consisting of lignin sulfonate, polycarboxylate, polycarboxylate
ether, melamine formaldehyde sulfonate, alkylphenol glycol ether
and naphthaline sulfonates, and wherein said at least one
stabilizer is or said at least two stabilizers are selected from
the group consisting of modified or unmodified, fully or partially
hydrolyzed polyvinyl alcohol, polyvinyl acetal, polyvinyl
pyrrolidone, polyalkylene glycol, polyalkylene oxide, agar-agar,
carob seed grain, pectin, poly(meth)acrylate thickeners,
(meth)acrylate thickeners, poly(meth)acrylamides, polyurethanes,
associative thickeners, gelatine an soy protein.
2. The additive according to claim 1, wherein at least one
dispersing agent and/or stabilizer enters with at least one further
component of the minerally setting building material compound
and/or the additive into a viscosity-increasing interaction in the
minerally setting building material compound mixed with water.
3. The additive according to claim 2, wherein the
viscosity-increasing interaction with the same mixing water
content, based on the dry content of the building material
compound, leads to an at least 50% increased flow time in
accordance with EN ISO 2431, while the degree of spread in
accordance with EN 12706 changes by less than 20%.
4. The additive according to claim 1, wherein the weight ratio of
the sum of the dispersing agents to the sum of the stabilizers is
about 500:1 to about 1:10.
5. The additive according to claim 1, wherein said at least one
dispersing agent is or said at least two dispersing agents are
polycarboxylate and/or polycarboxylate ether.
6. The additive according to claim 1, wherein said at least one
stabilizer is or said at least two stabilizers are modified or
unmodified, fully or partially hydrolyzed polyvinyl alcohol,
polyvinyl pyrrolidone, polyalkylene glycol and/or polyalkylene
oxide.
7. The additive according to claim 1, wherein in the minerally
setting building material compound mixed with water at least one
dispersing agent and/or stabilizer which enters into a
viscosity-increasing interaction with at least one further
component of the minerally setting building material compound
and/or the additive is a polymer containing carboxyl, hydroxyl,
ether, amide, amine, keto, aldehyde, carbamate, carbamide and/or
ammonium groups.
8. The additive according to claim 1, wherein the additive further
contains at least one component selected from the group consisting
of surface-active compounds, water-redispersible dispersion
powders, cellulose ethers, agents to reduce shrinkage and/or to
reduce efflorescence, agents to control the hydration of minerally
setting systems, hydrophobic agents, water retention agents,
fillers, anti-caking agents, cement and gypsum.
9. A process for the preparation of the additive according to claim
1, the process comprising: mixing the individual components with
one another in powder form, or at least one of the components is
present in liquid form and mixing the remaining components as
liquid and/or as powder with the component in liquid form, or
drying at least one of the components which is present in liquid
form, and adding the further components as liquid and/or as powder
before, during and/or after the drying, or adding the or part of
the individual components of the rheological additive as separate
components to the building material compound during the preparation
thereof and mixing with the further components of the building
material compound.
10. The minerally setting building material compound according to
claim 11, wherein said compound is selected from the group
consisting of a dry mortar, fresh mortar, concrete, shotcrete,
self-compacting concrete, plaster of Paris, plaster, shotplaster,
gypsum plaster, gypsum/cement plaster, cement/lime plaster, flow
bed mortar, repair mortar, tile grout, anchor mortar, bedding
mortar, flowable floor screed, a levelling compound, a
self-levelling flooring compound, a smoothing compound and a
trowelling compound.
11. A minerally setting building material compound containing the
rheological additive according to claim 1.
12. The building material compound according to claim 11, wherein
the building material compound contains about 0.01 to about 3.0 wt.
% of the rheological additive, based on the dry weight of the
building material compound.
13. The building material compound according to claim 11, wherein
the building material compound is a self-levelling flooring
compound, wherein the degree of spread of the self-levelling
flooring compound, measured in accordance with EN 12706, does not
deviate more than 10% and/or the flow time of the self-levelling
flooring compound, measured with a flow cup with a 6 mm nozzle in
accordance with EN ISO 2431, does not deviate more than 15% from
the self-levelling flooring compound with casein and without
rheological additive.
14. The additive according to claim 3, wherein the weight ratio of
the sum of the dispersing agents to the sum of the stabilizers is
about 500:1 to about 1:10.
15. The additive according to claim 3, wherein said at least one
dispersing agent is or said at least two dispersing agents are
polycarboxylate and/or polycarboxylate ether.
16. The additive according to claim 4, wherein said at least one
dispersing agent is or said at least two dispersing agents are
polycarboxylate and/or polycarboxylate ether.
17. The additive according to claim 4, wherein said at least one
stabilizer is or said at least two stabilizers are modified or
unmodified, fully or partially hydrolyzed polyvinyl alcohol,
polyvinyl pyrrolidone, polyalkylene glycol and/or polyalkylene
oxide.
18. The additive according to claim 5, wherein said at least one
stabilizer is or said at least two stabilizers are modified or
unmodified, fully or partially hydrolyzed polyvinyl alcohol,
polyvinyl pyrrolidone, polyalkylene glycol and/or polyalkylene
oxide.
19. The additive according to claim 4, wherein in the minerally
setting building material compound mixed with water at least one
dispersing agent and/or stabilizer which enters into a
viscosity-increasing interaction with at least one further
component of the minerally setting building material compound
and/or the additive is a polymer containing carboxyl, hydroxyl,
ether, amide, amine, keto, aldehyde, carbamate, carbamide and/or
ammonium groups.
20. The additive according to claim 7, wherein the additive further
contains at least one component selected from the group consisting
of surface-active compounds, water-redispersible dispersion
powders, cellulose ethers, agents to reduce shrinkage and/or to
reduce efflorescence, agents to control the hydration of minerally
setting systems, hydrophobic agents, water retention agents,
fillers, anti-caking agents, cement and gypsum.
Description
[0001] The invention pertains to a rheological additive that can
replace casein in minerally setting building material compounds,
processes for the preparation of the additive, the use thereof, as
well as building material compounds containing the rheological
additive.
[0002] In minerally setting compounds casein is often used as a
liquefier or superplasticiser. In particular in the case of
self-levelling levelling compounds, the use of casein leads to a
low yield point and a high plastic viscosity, which is highly
valued by the user especially in the case of application by hand.
Such casein-containing compounds as a rule are also less sensitive
regarding the amount of mixing water used, which is highly valued
by the person handling it. Moreover, the use of casein leads to
further advantages such as a low yield point, good levelling out of
the applied levelling compound, little film formation, optimal
processing time also after the application, good flowing together
of levelling compounds applied next to each other even after
different intervals of time, such as for instance when the
levelling compounds are applied at separate times, no or only low
sedimentation of the compound, which shows itself in al. in that
the compound does not wash out, which is also called bleeding. The
sum of these properties is often also called honey-like consistency
by the person skilled in the art, which is a good description of
the rheological properties obtained as a result of the casein.
[0003] When instead of casein synthetic superplasticisers such as
for instance melamine formaldehyde sulfoxylates, lignin sulfonates
or polycarboxylate ethers are used, such levelling compounds obtain
a quite different rheology, which at first sight is manifested by a
greatly reduced viscosity. In any case it is not possible to apply
these by hand in the thin layer thickness of typically 1-3 mm
required by the user. To this end it is important that the
levelling compound has a rheology which is the same as or at least
comparable with that of casein-containing levelling compounds.
[0004] An important drawback of casein is its strongly fluctuating
price, which moreover has risen strongly in the last few years.
Moreover, the quality of casein can also change, applicable if
necessary calls for an adjustment of the recipe. For this reason
there is a growing need to replace casein as raw material, with the
object of obtaining more constant raw material prices and a more
uniform quality. In any case, it is necessary that in particular
the rheological properties of the minerally setting compounds do
not change or change only insignificantly.
[0005] Thus DE 102 26 088 A1 describes an additive based on
modified polycarboxylates and water-soluble ethers of high polymer
polysaccharides, in particular water-soluble cellulose ethers with
a viscosity as 2% aqueous solution of at least about 1,000 mPas.
The use of this additive leads to comparable and in part clearly
superior properties such as for instance an improved water
retention.
[0006] WO 2006/002935 A1 describes a mixing composition with
dispersing effect, containing a copolymer based on unsaturated
mono- or dicarboxylic acid derivatives and oxyalkylene
glycol-alkenyl ethers and water-soluble sulfo groups-containing co-
and terpolymers with a number average molecular weight of 50,000 to
20,000,000 g/mol. The described mixing compositions should also be
suitable as solvents independent of the dispersing effect, in which
case they can also be used in self-levelling levelling compounds or
surfacers on the basis of their simultaneously stabilizing effect,
in particular as a substitute for casein.
[0007] However, the solutions proposed in the state of the art
cannot replace all rheological subtleties of casein and/or their
preparation is extremely complex and demanding.
[0008] Hence it is the object of the present invention to propose a
rheological additive which has a properties profile which is
identical or very similar to that of casein in various minerally
setting compounds and which is easy to prepare. In addition, it
should be possible to easily adapt the properties profile of
differently formulated compounds.
[0009] Surprisingly, it was found that the object can be attained
by means of a rheological additive that is suitable for use in a
minerally setting building material compound, wherein the
rheological additive contains [0010] at least two different
dispersing agents and at least one stabilizer, or [0011] at least
one dispersing agent and at least two different stabilizers,
wherein said at least one dispersing agent is or at least two
disperging agents are selected from the group of lignin sulfonate,
polycarboxylate, polycarboxylate ether, melamine formaldehyde
sulfonate, alkylphenol glycol ether and/or naphthaline sulfonates,
and wherein said at least one stabilizer is or at least two
stabilizers are selected from the group of modified or unmodified,
fully or partially hydrolyzed polyvinyl alcohol, polyvinyl acetal,
polyvinyl pyrrolidone, polyalkylene glycol, polyalkylene oxide,
agar-agar, carob seed grain, pectin, poly(meth)acrylate and/or
(meth)acrylate thickeners, poly(meth)acrylamides, polyurethanes,
associative thickeners, gelatine and/or soy protein.
[0012] It is often preferred that at least one dispersing agent
and/or stabilizer enters with at least one further component of the
building material compound and/or the additive into a
viscosity-increasing interaction in the minerally setting building
material compound mixed with water.
[0013] With the additive according to the invention it is possible
to replace at least 50 wt. %, preferably at least 75 wt. %, in
particular even 100 wt. % of the used casein with the rheological
additive. The present invention also includes the process and/or
the method for replacing these amounts of casein in minerally
setting building material compounds with the rheological additive
according to the invention.
[0014] Depending on the composition of the additive and the
minerally setting building material compound, this is used in
building material compound in an amount of at least about 5 wt. %,
preferably at least about 10 wt. %, in particular at least about 20
wt. %, and/or at most about 500 wt. %, preferably at most about 300
wt. %, in particular at most about 200 wt. %, based on the amount
of casein to be replaced.
[0015] Within the meaning of the invention, dispersing agents are
surface-active substances which as a rule adsorb on the surfaces of
the solid particles and increase the wetting with water and thus
the distribution (dispersion) of solid particles in a liquid.
According to the invention, this includes in particular
water-soluble compounds which, at 23.degree. C., as 10 wt. %
aqueous, pH-neutral and/or alkaline solution have no or no
substantial effect on the viscosity of water, i.e. the Brookfield
viscosity at 20 rpm should not be more than 100 mPas. Moreover, in
minerally setting building material compounds the dispersing agents
allow the mixing water content, based on the dry content of the
compound in question, to decrease without the degree of spread in
accordance with EN 12706 (see Chapter 3.1, implementation in
accordance with Chapter 8, Edition November 1999) undergoing
substantial change. Included among the dispersing agents according
to the invention are also plasticisers, liquefiers,
superplasticisers, cement superplasticisers, and water reducing
agents.
[0016] Preferred dispersing agents as a rule are organic polymers
with a mean molecular weight M.sub.w of about 500 to about 500,000,
preferably of about 1,000 to about 250,000. The dispersing agents
according to the invention in many cases are present in the
alkaline pH-range as ionic polymers and have a high charge density.
By a high charge density is meant within the meaning of the
invention that per monomer unit with ionic groups there are up to
10 other monomer units, preferably up to 5 other monomer units, in
particular up to 3 other monomer units.
[0017] Preferred dispersing agents are lignin sulfonates, including
lignosulfonates and/or modified lignosulfonates; polycarboxylates,
including low-molecular poly(meth)acrylic acids and the derivatives
thereof, polyhydroxycarboxylic acids, copolymers of linear or
cyclic C.sub.4- to C.sub.6-olefins and unsaturated ethylene
dicarboxylic acids, styrene-maleic acid copolymerisates and/or
vinyl ether-maleic acid copolymerisates; polycarboxylate ethers,
including copolymers of unsaturated mono- and/or dicarboxylic acid
derivatives and/or oxyalkylene glycol-alkenyl ethers;
melamine-formaldehyde-sulfonates, including melamine sulfonic
acid-formaldehyde condensates; naphthaline sulfonates, including
naphthaline-formaldehyde-sulfonates; and/or alkylphenol glycol
ethers. When the dispersing agents are present as salts, as a rule
magnesium, calcium, lithium, sodium and/or potassium salts are
preferred.
[0018] The proportions of the dispersing agent or dispersing agents
in the rheological additive are chosen such that their content in
the minerally setting building material compound is at least about
5 wt. %, preferably at least about 10 wt. %, in particular at least
about 20 wt. %, to at most about 400 wt. %, preferably at most
about 300 wt. %, in particular at most about 200 wt. %, based on
the amount of casein to be replaced.
[0019] The rheological additive according to the invention in
addition contains at least one stabilizer, with it also being
possible for different stabilizers to be combined with one another.
Such stabilizers allow the mixing water content in minerally
setting building material compounds to be increased without the
compound washing out or bleeding, which means that a part of the
water does not separate and that no water film is formed on the
surface. The stabilizers to be used within the meaning of the
invention in addition as a rule are water-soluble or
water-dispersible compounds which as 10 wt. % aqueous pH neutral
and/or alkaline solution or dispersion often, but not necessarily,
have a Brookfield viscosity at 20 rpm of more than 100 mPas even at
23.degree. C.
[0020] As stabilizers to be used according to the invention
synthetic and/or natural organic polymers can be employed, with
thickeners also being included.
[0021] Included among the stabilizers which are synthetically
prepared organic polymers are polyvinyl pyrrolidones and/or
polyvinyl acetals with a preferred molecular weight of 2,000 to
400,000, fully or partially hydrolyzed polyvinyl alcohols and the
derivatives thereof, which can be modified for instance with amino
groups, carboxylic acid groups and/or alkyl groups, with a degree
of hydrolysis of preferably about 70 to 100 mol. %, in particular
of about 80 to 98 mol. %, and a Hoppler viscosity as 4% aqueous
solution of preferably 1 to 100 mPas, in particular of about 3 to
50 mPas (measured at 20.degree. C. in accordance with DIN 53015).
Furthermore, it includes polyalkylene glycols and/or polyalkylene
oxides, such as polymerisates of propylene oxide and/or ethylene
oxide, with these preferably having a mean molecular weight M.sub.w
of about 1,000 to about 5,000,000, preferably of about 2,000 to
about 3,000,000, in particular of about 5,000 to about 1,000,000,
among which are also counted the copolymerisates and block
copolymerisates thereof, polyaddition products such as polyalkylene
oxides and polyalkylene glycols, in which case the alkylene group
typically is a C.sub.2- and/or C.sub.3-group, among which are also
counted polyethylene and/or polypropylene glycol, polyethylene
and/or polypropylene oxide and/or the copolymers and block
copolymers thereof. Furthermore, it also includes
poly(meth)acrylate and (meth)acrylate thickeners,
poly(meth)acryl-amides, polyurethanes and/or associative
thickeners.
[0022] Preferred synthetic organic polymeric stabilizers are in
particular partially saponified polyvinyl alcohols with a degree of
hydrolysis of 80 to 98 mol. % and a Hoppler viscosity as 4% aqueous
solution of 1 to 50 mPas, polyalkylene glycol and/or polyalkylene
oxide, in which case the alkylene group is a C.sub.2- and/or
C.sub.3-group, poly(meth)acrylate and (meth)acrylate thickeners,
poly(meth)acrylamides and/or polyurethanes. Water-soluble sulfo
groups-containing co- and terpolymers with a number average
molecular weight of 50,000 to 20,000,000 g/mol are less preferred
as components of the additive according to the invention.
[0023] Among the natural organic polymeric stabilizers are
biopolymers and the derivatives thereof. Among these are agar-agar,
carob seed grain, pectin, alginates, peptides and/or proteins.
Preferred proteins are gelatine and/or soy-protein.
[0024] The stabilizer or stabilizers of the rheological additive
are used in the minerally setting building material compound in an
amount of at least about 0.1 wt. %, preferably at least about 1 wt.
%, in particular at least about 5 wt. %, to at most about 350 wt.
%, preferably at most about 250 wt. %, in particular at most about
100 wt. %, based on the amount of casein to be replaced.
[0025] The weight ratio of the sum of the dispersing agents to the
sum of the stabilizers in the additive according to the invention
is about 500:1 to about 1:10, preferably about 300:1 to about 1:5,
in particular about 100:1 to about 1:2.
[0026] Surprisingly, it was found that the minerally setting
building material compound containing the inventive additive, when
mixed with water, obtains a rheology very similar to when casein is
used. This is in particular the case when at least one dispersing
agent and/or one stabilizer of the additive enters into a
viscosity-increasing interaction with at least one further
component of the building material compound and/or the additive in
the minerally setting building material compound mixed with
water.
[0027] The viscosity-increasing interaction of the at least one
dispersing agent and/or stabilizer manifests itself in that, upon
its addition, with the same mixing water content, based on the dry
content of the building material compound, the flow time in
accordance with EN ISO 2431 (Edition May 1996), measured according
to Chapter 7.2 with a flow cup with a nozzle diameter of 6 mm, is
increased by at least 50%, preferably by at least 100%, in
particular by at least 150%, and quite especially preferably by at
least 200%, while the degree of spread in accordance with EN 12706
changes by less than 20%, preferably less than 10%. To this end the
amount of the dispersing agent or dispersing agents and/or
stabilizer or stabilizers is chosen such that it is in accordance
with the additive according to the invention, in order to obtain
the desired properties. When it is not possible or too expensive to
determine this amount, each dispersing agent and/or stabilizer
contained in the additive is used in equal shares, with the sum of
the used dispersing agents and stabilizers corresponding to the
amount by weight of casein which is to be replaced.
[0028] Surprisingly, it was also concluded that as a result of the
addition of the inventive additive, and in particular when at least
one dispersing agent and/or stabilizer can undergo a
viscosity-increasing interaction, the minerally setting building
material compound mixed with water obtains a rheology with a low
yield point and high plastic viscosity, as is the case when casein
is used. Moreover, the building material compounds containing the
additive also obtain the honey-like rheology typical for
casein-containing compounds, even when the use of casein is fully
abstained from.
[0029] It is often preferred that at least one dispersing agent
and/or stabilizer of the additive enters into a
viscosity-increasing interaction with at least one further
component of the building material compound and/or the additive in
the minerally setting building material compound mixed with water.
This further component means a different component from the one
dispersing agent and/or stabilizer which enters into a
viscosity-increasing interaction, but can itself be such a
dispersing agent and/or stabilizer, which is part of the building
material compound and/or the additive. It is also possible that
this further component is neither a dispersing agent nor a
stabilizer, but has a quite different function. If an associative
thickener is present, it is most often preferred that also another
dispersing agent or stabilizer can undergo with at least one
further component a viscosity-increasing interaction.
[0030] It is often advantageous when at least one dispersing agent
and/or stabilizer which enters into a viscosity-increasing
interaction with a further component is a polymer with functional
groups. These can be ether, ester, nitrile, amide, amine, imine,
carboxyl, hydroxyl, keto, aldehyde, carbamate, carbamide,
carboxylic anhydride and/or ammonium groups. Quite especially
preferred are carboxyl, hydroxyl, amine, imine and/or ether
groups.
[0031] In order to bring about a particularly good interaction, it
is useful as a rule when the polymer with functional groups does
not contain more than 10 other monomer units, preferably not more
than 5 other monomer units, in particular not more than 2 other
monomer units per monomer unit with functional group.
[0032] In a quite particular embodiment the additive and/or the
minerally setting building material compound contain at least two
dispersing agents and/or stabilizers, which enter into a
viscosity-increasing interaction with one another. Often it is
preferred when these are part of the additive according to the
invention. Advantageously, both dispersing agents and/or
stabilizers are polymers of which the functional groups are at
least one carboxyl, hydroxyl, ether, ester, nitrile, amide, amine,
imine, keto, aldehyde, carbamate, carbamide, carboxylic anhydride
and/or ammonium group, with the nature of the functional groups of
the two dispersing agents and/or stabilizers differing one from the
other. Quite especially preferred are polymers which contain groups
which enter into interaction with one another by means of hydrogen
bridge bonds. Non-limiting examples of such groups are the carboxyl
groups of polycarboxylates and the hydroxyl groups of polyvinyl
alcohol, as well as the hydroxyl groups of polyvinyl alcohol and
the ether groups of polyethylene glycol.
[0033] The additive according to the invention can also contain
further components. Preferred further components are surface-active
compounds such as powdery and/or liquid wetting agents,
anti-foaming agents and/or tensides, alkyl, hydroxyalkyl and/or
alkylhydroxyalkyl polysaccharide ethers such as cellulose ether,
starch ether and/or guar ether, with the alkyl and the hydroxyalkyl
group typically being a C.sub.1- to C.sub.4-group, dextrins,
glucosaccharides, biopolymers such as gum arabic, gum tragacanth,
synthetic polysaccharides such as anionic, nonionic or cationic
heteropolysaccharides, in particular xanthan gum, welan gum, and
diutan gum, dispersing agents, further rheology control additives
such as for instance casein, agents to control the hydration of
minerally setting systems, in particular setting accelerators,
solidification accelerators and/or setting retarders,
air-entraining agents, dispersions and water-redispersible
dispersion powders based on water-insoluble film-forming polymers
such as for instance on the basis of vinyl acetate, ethylene-vinyl
acetate, ethylene-vinyl acetate-vinyl versatate, ethylene-vinyl
acetate-(meth)acrylate, ethylene-vinyl acetate-vinyl chloride,
vinyl acetate-vinyl versatate, vinyl acetate-vinyl
versatate-(meth)acrylate, vinyl versatate-(meth)acrylate, pure
(meth)acrylate, styrene-acrylate and/or styrene-butadiene, in which
case vinyl versatate preferably is a C.sub.4- to C.sub.12-vinyl
ester and the polymerisates can contain about 0-50 wt. %, in
particular about 0-30 wt. %, and quite especially preferably about
0-10 wt. % of further monomers, in particular those with functional
groups, hydrophobic agents and/or additives for reduction of the
water absorption capacity, in particular based on silanes,
siloxanes, silicones, metal soaps, fatty acids and/or fatty acid
esters, additives for the reduction of shrinkage and/or
efflorescence, such as for instance compounds based on natural
resins, in particular colophonium and/or the derivatives thereof,
fibres such as cellulose fibres, additives for the entry of air
voids, water retention agents, pigments, anti-caking agents,
fillers and/or aggregates such as quartzitic and/or carbonatic
sands and/or powders such as for instance quartz sand and/or
limestone powder, carbonates, silicates, chalks, layered silicates,
precipitated silicas, light-weight fillers such as for instance
hollow microspheres of glass, fly ash, microsilica, highly
dispersed and/or pyrogenic silicas, polymers such as polystyrene
spheres, aluminosilicates, silica, aluminium-silica,
calcium-silicate hydrate, silicon dioxide, aluminium-silicate,
magnesium-silicate, aluminium-silicate hydrate,
calcium-aluminium-silicate, calcium-silicate hydrate,
aluminium-iron-magnesium-silicate, calcium metasilicate, clays such
as vermiculites and bentonite and/or vulcanic slag, as well as
pozzolanes such as metakaolin, latent hydraulic components, cement
and/or gypsum, in which case the fillers and/or light-weight
fillers can also have a natural or artificially generated colour.
Preferred light-weight fillers are perlites, celites, cabosil,
circosil, eurocell, fillites, promaxon, vermex and/or
wollastonite.
[0034] Quite especially preferred additives are polymer
dispersions, dispersion powders, fillers, anti-caking agents,
polysaccharide ethers, hydrophobic agents, in particular silanes,
silane esters, siloxanes, fatty acids and/or fatty acid esters,
water retention agents, as well as additives to control the
shrinkage and/or the reduction of efflorescence.
[0035] For surface-active substances for instance, the content of
these additives can be very low and be in the range of about 0.01
wt. % or more, in particular about 0.1 wt. % and more, but as a
rule it should not exceed about 10 wt. %, in particular about 5 wt.
%. On the other hand, for instance the content of
water-redispersible polymer powder and/or fillers can be higher and
can even be the 1,000-fold amount or more of the rheological
additive according to the invention.
[0036] The additive according to the invention can be present as
liquid, powder, granulate and/or flakes and preferably is
water-soluble or readily dispersible in water. Often it is
advantageous when the additive is a powder or granulate and/or
consists of flakes. Because of this the additive can easily be
worked into a dry mixture already at the factory, which makes
possible exact dosing and a homogeneous distribution and makes its
preparation particularly easy and economical. For use this dry
mixture then only has to be mixed with the appropriate amount of
water and applied, which brings many advantages with it, such as
for instance easy handling, simplified logistics and/or resistance
to freeze-thaw.
[0037] According to the invention, processes for the preparation of
the additive are also claimed. In a preferred embodiment the
individual components are mixed with one another in powder form, in
which process commercially available mixers can be used. In a
further preferred embodiment, when at least one of the components
is present in liquid form, the remaining components are mixed as
liquid and/or as powder with the component in liquid form. In
another preferred embodiment, when at least one of the components
is present in liquid form, it is dried, in which case the further
components are added as liquid and/or as powder before, during
and/or after the drying. In yet another preferred embodiment the or
part of the individual components of the rheological additive are
added as separate components to the building material compound
during the preparation thereof and are mixed with the further
components of the building material compound. In this embodiment
the building material compound can be a dry mixture which is mixed
with water later on immediately prior to being used, or it can
already be mixed with water. In the case of 2-component systems,
the additive or parts of the additive can be added to the liquid
and/or powdery components, and/or be fed additionally during the
mixing process, for instance with the mixing water.
[0038] When the process has a drying step, drying can take place by
means of every suitable process. Preferred are spray drying, freeze
drying, fluidized bed drying, drum drying and/or flash drying, in
which case spray drying is particularly preferred and the spraying
can take place for instance by means of a spraying wheel,
one-component or multi-component nozzle. If necessary, the mixture
to be dried can still be diluted with water, in order to achieve a
suitable viscosity for the drying. The drying temperature in
principle has no real limits. In particular because of
safety-related considerations, however, it should not, as a rule,
exceed about 200.degree. C., in particular about 175.degree. C. In
order to attain sufficiently efficient drying, temperatures of
about 110.degree. C. or higher, in particular of about 120.degree.
C. or higher, are preferred.
[0039] The rheological additive according to the invention is
suitable for use in minerally setting building material compounds,
with the minerally setting building material compound preferably
being a dry mortar, fresh mortar, concrete, shotcrete, dry
concrete, self-compacting concrete, reinforced concrete, cellular
concrete, aerated concrete, foamed concrete, plaster of Paris,
plaster, shotplaster, gypsum plaster, gypsum/cement plaster,
cement/lime plaster, flow bed mortar, thermal insulation mortar,
repair mortar, tile grout, plywood mortar, grouting mortar,
cementitious coatings for concrete, bedding mortar, injection
mortar, anchor mortar, bonding mortar, sealing compounds, cement
primers, ceramic tile adhesives, joint adhesives, powder coatings,
parquet adhesives, flowable floor screed, cementitious floor
screed, cementitious rapid setting screed, a levelling compound,
self smoothing flooring compound, self-levelling flooring compound,
smoothing compound and/or trowelling compound.
[0040] The minerally setting building material compound contains at
least one mineral binder. By this are meant within the meaning of
the invention binders which as a rule are powdery and in particular
consist of at least a) one hydraulically setting binder, b) a
latent hydraulic binder, and/or c) a non-hydraulic binder which
reacts under the influence of air and water.
[0041] As preferred hydraulically setting binders can be used
cement, in particular Portland cement, for instance in accordance
with EN 196 OEM I, II, III, IV and/or V, calcium-aluminate-cements
such as for instance high-alumina cement and/or gypsum, by which
are meant in the meaning of this invention in particular calcium
sulfate in the form of .alpha.- and/or .beta.-semihydrate and/or
anhydrite of form I, II and/or III. As latent hydraulic binders
pozzolanes such as metakaolin, calcium metasilicate and/or vulcanic
slag, vulcanic tuff, trass, fly ash, acid blast-furnace slag and/or
silica dust can be used, which react hydraulically in combination
with a calcium source such as calcium hydroxide and/or cement. As
non-hydraulic binder which reacts under the influence of air and
water there can be used in particular lime, for the most part in
the form of calcium hydroxide and/or calcium oxide. Preferred above
all are pure Portland cement-based construction material compounds
or a mixture of Portland cement, calcium-aluminate cement, and
calcium sulfate, with it being possible, if so desired, to still
add latent hydraulic and/or non-hydraulic binders to both
systems.
[0042] According to the invention, minerally setting building
material compounds containing the rheological additive according to
the invention are also claimed. The additive and/or individual
components of the additive can be added to the building material
compound in the preparation of the dry mixture, such as for
instance dry mortars. To this end it is advantageous when the
additive is present in solid form such as powder, granulate and/or
flakes. However, the additive and/or individual components can also
be dosed in solid and/or in liquid form shortly before and/or
during the mixing with water.
[0043] The claimed minerally setting building material compounds
can be formulated as dry mortar, fresh mortar, concrete, shotcrete,
dry concrete, self-compacting concrete, reinforced concrete,
cellular concrete, aerated concrete, foamed concrete, plaster of
Paris, plaster, shotplaster, gypsum plaster, gypsum/cement plaster,
cement/lime plaster, flow bed mortar, thermal insulation mortar,
repair mortar, tile grout, grouting mortar, plywood mortar,
cementitious coatings for concrete, bedding mortar, injection
mortar, anchor mortar, bonding mortar, sealing compounds, cement
primers, ceramic tile adhesives, joint adhesives, powder coatings,
parquet adhesives, flowable floor screed, cementitious floor
screed, cementitious rapid setting screed, levelling compounds,
self smooting flooring compounds, self-levelling flooring
compounds, smoothing compounds and/or trowelling compounds.
[0044] Quite especially preferred are building material compounds
in the form of mixtures, in particular dry mortar mixtures, which
are formulated as levelling compounds, flowable floor screeds, self
smoothing flooring compounds, smoothing compounds and/or trowelling
compounds as well as self-levelling flooring compounds, and which
are mixed with water only shortly before application.
[0045] Surprisingly, it was found that with the additive according
to the invention minerally setting building material compounds can
be formulated which have properties which are similar to those of
casein-containing compounds. Thus dry mortars and/or water-based
formulations, in particular levelling compounds, levellers, floor
screeds, smoothing compounds and/or trowelling compounds as well as
self-levelling flooring compounds, of which the properties are
similar to those of casein-containing compounds, can be prepared in
an easy way. Quite especially preferred are self-levelling flooring
compounds with these properties, where the degree of spread,
measured in accordance with EN 12706, does not deviate more than
10% and/or the flow time of the self-levelling flooring compound,
measured with a flow cup with a 6 mm-nozzle in accordance with EN
ISO 2431 (Chapter 7.2), does not deviate more than 15% from the
self-levelling flooring compound containing the normal amount of
casein (100 wt. % casein) and without rheological additive
according to the invention. This 100 wt. % casein is based on the
amount of casein which the skilled person uses without the additive
according to the invention in order to obtain the preferred
properties of commercially available, casein-containing
self-levelling flooring compounds generally known to the skilled
person.
[0046] The claimed building material compounds contain about 0.01
to about 3.0 wt. %, preferably about 0.05 to about 2.0 wt. %, in
particular about 0.1 to about 1.0 wt. % of rheological additive,
based on the dry content of the building material compound.
[0047] The rheological additive according to the invention is easy
to prepare, since as a rule commercially available products can be
used. When it is present in solid form, in particular as powder,
granulate and/or flakes, it typically has a very good wettability
and as a rule also has a good solubility or dispersibility, so that
already on contact with water it is fully dissolved or dispersed
within a few seconds, in any case through light stirring. In
addition, it can be used in many different ways and is very readily
miscible and storable with all sorts of dry mortar mixtures.
Moreover, it is possible without great expense to adjust the
rheological additive to specific formulations of the building
material compounds without new polymers having to be prepared in a
costly manner. The use of the additive according to the invention
moreover make it possible for the formulator to replace the casein
used in the existing recipes of his building material compounds in
an easy way, as a result of which his raw materials costs are no
longer dependent on those of casein.
[0048] The invention is further elucidated with reference to the
following examples. Unless indicated otherwise, the tests are
carried out at a temperature of 23.degree. C. and a relative
humidity of 50%.
Substances Used and their Abbreviations: [0049] PCE commercially
available, modified powdery polycarboxylate ether; pH-value of the
20% aqueous solution is 6.5-8.5. [0050] PVOH partially hydrolyzed
powdery polyvinyl alcohol with a degree of hydrolysis of 88% and a
Hoppler viscosity as 4% aqueous solution of 40 mPas. [0051] PEG
powdery polyethylene glycol with a molecular weight of about
16,000. [0052] Na-AA sodium salt of a water-soluble acrylic acid
copolymer powder with a sodium content (as Na.sub.2O) of 18.9%.
[0053] casein casein 110 mesh. [0054] CE commercially available
powdery hydroxyethyl cellulose with a Brookfield viscosity as 2%
aqueous solution of 400-700 mPas at 20 rpm.
Preparation of the Additives:
Additive 1:
[0055] 33.4 parts by weight of PCE, 33.3 parts by weight of PVOH,
and 33.4 parts by weight of PEG were homogeneously mixed with one
another using a stirrer. The result was a homogeneous, free-flowing
additive which is easy to dose and easily wettable.
Additive 2:
[0056] 35 parts by weight of PCE, 32.5 parts by weight of PVOH, and
32.5 parts by weight of Na-AA were homogeneously mixed with one
another using a stirrer. The result was a homogeneous, free-flowing
additive which is easy to dose and easily wettable.
Additive 3 (Comparative):
[0057] Instead of an additive according to the invention 0.40 parts
by weight of casein and 0.05 parts by weight of CE were directly
added to the dry mortar formulation according to Table 3.
EXAMPLE 1
[0058] From the individual dispersing agents or stabilizers 10 wt.
% aqueous solutions were prepared, while the powdery dispersing
agents and stabilizers were mixed with the appropriate amount of
water and left to stand for 24 hours (Experiments 1-1 to 1-4). The
Brookfield viscosity was measured at 20 and 100 rpm. In order to
examine the interaction of the individual dispersing agents or
stabilizers with the other components of Additives 1 and 2, the 10
wt. % solutions in question were mixed with one another in the
specified weight ratios (see Tables 1 and 2), in which process a
possible interaction was observed immediately (Experiment of Table
2) or within a few minutes (Experiment of Table 1). The mixtures
were left to stand for 24 hours before the Brookfield viscosities
were measured.
TABLE-US-00001 TABLE 1 The measured Brookfield viscosities of the
individual dispersing agents and stabilizers as 10 wt. % solutions
and of the different combinations according to the ratios present
in Additive 1, measured in all cases at 20 and 100 rpm. Unless
specified otherwise, Spindle 3 was used. Experiment BV .sup.b)
[mPas] No. DM or SM .sup.a) Weight ratio 20 rpm 100 rpm 1-1 (Ref.)
PCE 10 .sup. 25 .sup. 1-2 (Ref.) PVOH 3,200 .sup.c) 2,684 .sup.c)
1-3 (Ref.) PEG 15 .sup. 32 .sup. 1-4 (Ref.) PCE/PVOH 50:50 110
.sup. 107 .sup. 1-5 (Ref.) PCE/PEG 50:50 15 .sup. 29 .sup. 1-6
(Ref.) PVOH/PEG 50:50 .sup.d) .sup.d) 1-7 PCE/PVOH/ 33.4:33.3:33.3
.sup.d) .sup.d) PEG .sup.a) DM stands for dispersing agent, SM for
stabilizer. .sup.b) BV stands for Brookfield viscosity. .sup.c)
Spindle 5 was used. .sup.d) A homogeneous solution was not
obtained. In the mixture within a few minutes gel-like aggregates
are formed, which cannot be broken any more by stirring. When the
mixture is left to stand overnight, 2 phases are formed (an aqueous
phase and a gel-like one).
[0059] The results of Table 1 show impressively that the PCE used
does not enter into a viscosity-increasing interaction with the two
other components present in Additive 1. Rather, the viscosity of
the used polyvinyl alcohol solution decreases many times over when
it is mixed with the aqueous PCE solution (Exp. Nos. 1-4). When on
the other hand the two non-ionic aqueous solutions of PVOH and PEG
are mixed with one another (Exp. Nos. 1-6), a high-viscous gel is
formed, in which process also part of the water is exsolved, which
clearly demonstrates the viscosity-increasing interaction.
TABLE-US-00002 TABLE 2 The measured Brookfield viscosities of the
individual dispersing agents and stabilizers as 10 wt. % solutions
and of the different combinations according to the ratios present
in Additive 2, measured in all cases at 20 and 100 rpm. Unless
specified otherwise, Spindle 3 was used. Experiment BV .sup.b)
[mPas] No. DM or SM .sup.a) Weight ratio 20 rpm 100 rpm 2-1 (Ref.)
PCE 10 .sup. 25 .sup. 2-2 (Ref.) PVOH 3,200 .sup.c) 2,684 .sup.c)
2-3 (Ref.) Na-AA 5 .sup. 14 .sup. 2-4 (Ref.) PCE/PVOH 50:50 110
.sup. 107 .sup. 2-5 (Ref.) PCE/Na-AA 50:50 10 .sup. 19 .sup. 2-6
(Ref.) PVOH/Na-AA 50:50 .sup.d) .sup.d) 2-7 PCE/PVOH/
35.0:32.5:32.5 .sup.d) .sup.d) Na-AA .sup.a)-c) Legend see Table 1.
.sup.d) The mixture flocculates.
[0060] The results of Table 2 likewise show that the PCE used does
not enter into a viscosity-increasing interaction with the Na-AA
present in Additive 2 either. When on the other hand the aqueous
solutions of PVOH and Na-AA are mixed with one another (Exp. Nos.
2-5), immediately flocculates are formed which cannot be stirred up
again.
EXAMPLE 2
[0061] A dry mortar formulation according to Table 3 was prepared.
The amounts used according to Tables 3 and 4 of the individual
dispersing agents and stabilizers were weighed in and homogeneously
mixed with the dry mortar formulation. Next, in each case 100 g of
the obtained dry mortar formulation were stirred with a 60 mm
propeller stirrer at a rate of 950 rpm for 60 seconds, with the
corresponding amount of mixing water being added with stirring.
After a maturing time of 3 minutes, the mortar prior to being
measured was again blended for 15 seconds with the stirrer, and the
degree of spread was measured in accordance with EN 12706 (Chapter
8) and the flow time of the mortar was determined in a Ford cup in
accordance with DIN 53211 with a 6 mm nozzle, with the mortars
being separately mixed for the two measurements.
TABLE-US-00003 TABLE 3 Dry mortar formulation of the used smoothing
compound. As mixing water were used 21 parts by weight water on 100
parts by weight of dry mortar formulation. PZ Anneliese Milke 52,5R
premium 23.00 wt. % HAC Fondu Lafarge 12.00 wt. % calcium hydrate
1.00 wt. % hard moulding plaster No. 1 4.10 wt. % quartz sand
0.1-0.3 mm 42.43 wt. % calcium carbonate Omyacarb .RTM. 10 BG 15.00
wt. % setting retarder 0.15 wt. % powder defoamer 0.12 wt. %
lithium carbonate 0.20 wt. % dispersion powder ELOTEX .RTM. FL 4200
2.00 wt. %
TABLE-US-00004 TABLE 4 The measured degree of spread in accordance
with EN 12706 and measured flow times in accordance with EN ISO
2431 for the mixed dry formulation according to Table 3 and for the
individual dispersing agents and stabilizers as well as the
different combinations with the ratios present in Additive 1.
Amount Flow- DM or used.sup.b) Spread.sup.c) time.sup.d) Experiment
No. SM.sup.a) [wt. %] [mm] [sec] Observations 3-1 (Ref.) none 0.0
45 --.sup.e) firm 3-2 (Ref.) PCE 0.2338 198 25 compound
bleeds.sup.f) 3-3 (Ref.) PVOH 0.2331 50 --.sup.e) firm 3-4 (Ref.)
PEG 0.2331 45 --.sup.e) firm 3-5 (Ref.) PCE 0.2338 160 59 PVOH
0.2331 3-6 (Ref.) PCE 0.2338 179 34 compound PEG 0.2331
bleeds.sup.f) 3-7 PCE 0.2338 160 92 Additive 1 PVOH 0.2331 PEG
0.2331 3-8 (Ref.) PVOH 0.2331 50 --.sup.e) firm PEG 0.2331 3-9
(Ref.) casein 0.4000 161 86 Additive 3 CE 0.0500 (comparative)
.sup.a)See Table 1 .sup.b)The amounts used are based on 100 wt. %
dry mortar formulation from Table 3. .sup.c)The degree of spread
was determined in accordance with EN 12706. .sup.d)The flow time
was determined with a flow cup with a 6 mm nozzle in accordance
with EN ISO 2431. .sup.e)The compound was too high-viscous to flow
through the 6 mm nozzle. .sup.f)The compound washes out and is
precipitated, i.e. it bleeds.
[0062] From Tables 4 and 5 it becomes clear that the use of PCE is
important in order to obtain a flowable smoothing compound. This is
shown on the one hand in Experiment 3-1 (Reference), where neither
a dispersing agent nor a stabilizer is added, as well as in
Experiment 3-8, where the smoothing compound contains PVOH as well
as PCE. It is true that Experiment 4-7, containing PVOH as well as
Na-AA, also has certain smoothing properties, since Na-AA as
dispersing agent has a diluting effect. As a result the flow time
becomes comparable with that of Experiment 3-9. However, the degree
of spread is clearly too low. Nor can the values of Experiment 3-9
be obtained by changing the amount used and/or the ratio.
[0063] When on the other hand even a small amount of PCE is admixed
(Experiments 3-2 and 4-1), this brings about a clearly higher
degree of spread as well as a low flow time. When the mixing water
content is reduced in order to prevent washing out, and/or the
proportion of PCE is decreased, it is true that a degree of spread
which is similar to that of Experiment 3-9 can be obtained. The
flow time, however, never increases to that of casein.
TABLE-US-00005 TABLE 5 The measured degree of spread in accordance
with EN 12706 and measured flow times in accordance with EN ISO
2431 for the mixed dry formulation according to Table 3 and for the
individual dispersing agents and stabilizers as well as the
different combinations with the ratios present in Additive 2.
Amount Flow DM or used.sup.b) Spread.sup.c) time.sup.d) Experiment
No. SM.sup.a) [wt. %] [mm] [sec] Observations 3-1 (Ref.) none 0.0
45 --.sup.e) firm 4-1 (Ref.) PCE 0.1750 190 26 compound
bleeds.sup.f) 4-2 (Ref.) PVOH 0.1625 55 --.sup.e) firm 4-3 (Ref.)
Na-AA 0.1625 168 52 slight bleeding.sup.f) 4-4 (Ref.) PCE 0.1750
173 44 slight PVOH 0.1625 bleeding.sup.f) 4-5 (Ref.) PCE 0.1750 175
47 slight Na-AA 0.1625 bleeding.sup.f) 4-6 PCE 0.1750 158 83
Additive 2 PVOH 0.1625 Na-AA 0.1625 4-7 (Ref.) PVOH 0.1625 140 71
Na-AA 0.1625 3-9 (Ref.) casein 0.4000 161 86 Additive 3 CE 0.0500
(comparitive) Legend see Table 4.
[0064] It is true that because of the addition of PEG (Experiment
3-6) or PVOH (Experiments 3-5 and 4-4) to PCE the viscosity of the
smoothing compound increases slightly, which shows itself in a
lower degree of spread and a slightly increased flow time. However,
it is not possible to set both the degree of spread and the flow
time of the smoothing compound with casein only with two dispersing
agents and/or stabilizers, even when the content of the individual
dispersing agents and/or stabilizers and/or the mixing water
content is changed. When on the other hand a combination of all 3
components, such as are present for instance in Additive 1
(Experiment 3-7) and Additive 2 (Experiment 4-6), is mixed
together, the degree of spread as well as the flow time sets itself
such as if casein were used. The flow time in particular increases
very strongly, without having a negative effect on the degree of
spread. In the case of Additive 1 this is attributed to the
interaction between PEG (contains many ether groups) in Additive 1,
or of Na-AA (contains many carboxyl groups) in Additive 2, and PVOH
(contains many hydroxyl groups). As an additional effect the
combination of dispersing agents and/or stabilizers according to
the invention can also replace the proportion of cellulose ether
entirely or, depending on the recipe, at least in part, as is
obvious from Examples 3-7 and 4-6.
[0065] Surprisingly, it has been shown that because of the additive
according to the invention not only the degree of spread and the
flow time can be set to values such as if casein were used. But the
other important properties of casein-containing smoothing
compounds, in particular the flow properties at lower as well as
higher viscosities, the stabilizing properties, the capacity to
cover over raw material variations, in particular of cements and
fillers, a good water retention capacity, a high abrasion
resistance of the cured compound, as well as the setting behaviour
of the compound astonishingly also set themselves such as if casein
were used.
* * * * *